Jiang Kunlun, Yang Wenjian, Zhang Zhaobing, Zhang Yongli, Lan Jing, Chen Dehao, Li Wenzhe, Fan Jiandong
Institute of New Energy Technology, Jinan University, Guangzhou 510632, China.
Department of Ecology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
ACS Appl Mater Interfaces. 2025 Jan 15;17(2):3631-3643. doi: 10.1021/acsami.4c18560. Epub 2024 Dec 31.
CsSbBr, as a sort of novel lead-free perovskite single crystal, has the merits of high carrier mobility and a long diffusion length. However, the large-sized and high-crystallized CsSbBr single crystals are not easily obtained. Herein, we apply the vertical Bridgman method to grow centimeter-sized CsSbBr single crystal. The temperature-dependent crystal structure of CsSbBr is characterized in the temperature range of 100-400 K. A novel crystallographic and electronic structure anisotropy of the as-grown CsSbBr single crystal along the transmission directions of [100] and [001] is experimentally and theoretically proved. Owing to the layered two-dimensional (2D) structure of CsSbBr, quantum confinement effects prolong the lifetime of hot carriers, leading to their accumulation within the Sb-Br plane along the [100] direction, thereby resulting in a higher density of electronic states. Accordingly, the [100] device exhibits a carrier mobility higher than that of the [001] device, with the [100] device mobility being 4 orders of magnitude higher than that of the [001] device at 423 K, showing a remarkable anisotropy. The [100] device also shows responsivity ∼10 times higher than that of the [001] device.
溴化铯锑（CsSbBr）作为一种新型无铅钙钛矿单晶，具有载流子迁移率高和扩散长度长的优点。然而，大尺寸且高结晶度的溴化铯锑单晶并不容易获得。在此，我们采用垂直布里奇曼法生长厘米级的溴化铯锑单晶。在100 - 400 K的温度范围内对溴化铯锑的温度依赖性晶体结构进行了表征。通过实验和理论证明了所生长的溴化铯锑单晶沿[100]和[001]传输方向存在一种新的晶体学和电子结构各向异性。由于溴化铯锑的层状二维（2D）结构，量子限制效应延长了热载流子的寿命，导致它们在沿[100]方向的Sb - Br平面内积累，从而产生更高的电子态密度。因此，[100]器件的载流子迁移率高于[001]器件，在423 K时，[100]器件的迁移率比[001]器件高4个数量级，表现出显著的各向异性。[100]器件的响应度也比[001]器件高约10倍。
